The method quoted looks unfairly drawn out compared with, eg.
1.Tap on any preset voice category, or if already in a preset voice category, go straight to 2.
2.Tap Up arrow (bottom right of screen),
3.Go to Page2 and the legacy folder is there so tap on it.
Step 1 and any steps beyond 3 are common whether you are using a preset or legacy voice.
If you already have a Legacy voice loaded you can always go straight back to Legacy (without having to go through the above) if you push the corresponding Part Select button. You're taken back to the folder in Legacy where that voice is stored so can explore all categories straightaway.
John